PLASMA-MEMBRANE FATTY ACID-BINDING PROTEIN AND MITOCHONDRIAL GLUTAMIC-OXALOACETIC TRANSAMINASE OF RAT-LIVER ARE RELATED
PLASMA-MEMBRANE FATTY ACID-BINDING PROTEIN AND MITOCHONDRIAL GLUTAMIC-OXALOACETIC TRANSAMINASE OF RAT-LIVER ARE RELATED
复制标题
DOI：
10.1073/pnas.87.9.3484
复制
发表时间：
1990-05-01
影响因子：
11.1
通讯作者：
THUNG, S
中科院分区：
文献类型：
--
作者：
BERK, PD;WADA, H;THUNG, S
肝质膜脂肪酸结合蛋白(h-FABPPM)和大鼠肝脏谷氨酸草酰乙酸转氨酶(mGOT)的线粒体同工酶具有相似的氨基酸组成和相同的残基3-24的氨基酸序列。两种蛋白质在 SDS/聚丙烯酰胺凝胶电泳上以 43 kDa 的表观分子量迁移，在等电聚焦上具有相似的碱性电荷异构体模式，从四种不同的高效液相色谱柱中类似地洗脱，在酸性条件下在 435 nm 处和 pH 8.3 下在 354 nm 处具有最大吸收，并以 Ka 值结合油酸盐。 1.2-1.4倍107 M-1。正弦富集的肝脏质膜和纯化的 h-FABPPM 具有 GOT 酶活性；膜和纯化蛋白的相对比活性（单位/毫克）表明h-FABPPM 构成大鼠肝细胞质膜蛋白的1-2%。针对 h-FABPPM 的单特异性兔抗血清与 mGOT 进行蛋白质印迹反应，反之亦然。针对这两种蛋白的抗血清在大鼠肝细胞中产生质膜免疫荧光，并选择性抑制肝细胞对[3H]油酸盐的摄取，但不抑制[35]磺溴酞或[14C]牛磺胆酸盐的摄取。抗-h-FABPPM产生的油酸摄取抑制可以通过将抗血清与mGOT预孵育来消除；类似地，任一抗血清产生的质膜免疫荧光可以通过与另一种抗原预孵育来消除。这些数据表明 h-FABPPM 和 mGOT 密切相关。
The hepatic plasma membrane fatty acid-binding protein (h-FABPPM) and the mitochondrial isoenzyme of glutamic-oxaloacetic transaminase (mGOT) of rat liver have similar amino acid composition and identical amino acid sequences for residues 3-24. Both proteins migrate with an apparent molecular mass of 43 kDa on SDS/polyacrylamide gel electrophoresis, have a similar pattern of basic charge isomers on isoelectric focusing, are eluted similarly from four different high-performance liquid chromatographic columns, have absorption maxima at 435 nm under acid conditions and 354 nm at pH 8.3, and bind oleate with a Ka .apprxeq. 1.2-1.4 .times. 107 M-1. Sinusoidally enriched liver plasma membranes and purified h-FABPPM have GOT enzymatic activity; the relative specific activities (units/mg) of the membranes and purified protein suggest that h-FABPPM constitutes 1-2% of plasma membrane protein in the rat hepatocyte. Monospecific rabbit antiserum against h-FABPPM reacts on Western blotting with mGOT, and vice versa. Antisera against both proteins produce plasma membrane immunofluorescence in rat hepatocytes and selectively inhibit the hepatocellular uptake of [3H]oleate but not that of [35]sulfobromophthalein or [14C]taurocholate. The inhibition of oleate uptake produced by anti-h-FABPPM can be eliminated by preincubation of the antiserum with mGOT; similarly, the plasma membrane immunofluorescence produced by either antiserum can be eliminated by preincubation with the other antigen. These data suggest that h-FABPPM and mGOT are closely related.